The present disclosure relates to well tools that utilize shear members.
Many well tools have components pinned together by a shear member. A shear member is pin, a screw, or other member that spans the shear plane between two components to fix the components against movement in a direction along their shear plane. The shear member is designed to fail under a specified shear loading, thus holding the components against relative movement until the specified shear loading is achieved. In designing shear members, a balance must be achieved between the specified shear load at which the shear member fails and ancillary loads that may be encountered by the components. For example, if the designed specified shear loading is too low, the shear member may unintentionally shear. If the designed specified shear loading is too high, there may be circumstances when it is difficult or impossible to shear the shear member. In the context of a tool for use in a well, the need for balance is particularly accute, because of the environment. For example, the components of the tool may be subjected to shear loads, both constant and impact, as the tool is moved uphole and downhole in the well or as the tool is otherwise manipulated. Further, if the shear member prematurely shears, the tool may not function and then require a lengthy and costly trip to the surface to reset the tool.
Like reference symbols in the various drawings indicate like elements.